The word isos and Stacy are derived from the Greek word and they mean the standstill and are in balance and is a state of the gravitational equilibrium between the earth crusts.
And this concept explains the occurrence of the variation in the heights of the earth's crust landmass and it's said to be in equilibrium when a certain area of the surface reaches that state.
It's an important way to explain the negative feedback mechanism of the system.
the answer to your question is called a destructive plate boundary. this is when the more denser plate goes underneath the lesser dense plate. <span />
